Dual panel system for controlling the passage of light through architectural structures

ABSTRACT

The invention comprises a transparent/translucent panel system including two spaced flat panels and a series of elongated, abutting, rotatably mounted transparent/translucent light-controlling members disposed between the panels in which the light-controlling members are at least partially tubular or have annular members along their length to facilitate rotation of the light-controlling members and include a light-blocking surface whereby differently sized light-controlling members may be used and the light-controlling members, when rotated by a simple drive mechanism, can vary the light passing through the panel system from clear to opaque and can effectively block light between adjacent light-controlling members.

This application is a continuation of U.S. patent application Ser. No.10/600,261, filed Jun. 20, 2003. The entire disclosure of the foregoingpatent application is hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to architectural structures designed to passlight and, more particularly, to transparent/translucent panel systemsfor controlling the level of light admitted through sloped glazing,skylights, roofs, walls, and other architectural structures designed topass light.

BACKGROUND OF THE INVENTION

Various types of transparent and translucent glazing systems areavailable for the construction of sloped glazing, skylights, roofs,walls, and other architectural structures designed to pass light fordaylighting interiors and other purposes. When using such glazingsystems, it is often desirable to optimize the system's shadingcoefficient by reducing solar heat gain on hot summer days and duringpeak sunlight hours year round, while providing maximum light on coldwinter days and when it is most needed. It is often necessary tominimize glare and direct sunlight at peak sunlight periods, to ensurecomfort of those who occupy the space exposed to the glazing system. Ifarchitects and space planners can be liberated from the constraints offixed light transmission, they can maximize interior daylight withoutthe burden of unmanaged heat gain or discomforting glare.

Indeed, if the level of light passing through sloped glazing, skylights,roofs, walls, and other architectural structures designed to pass lightcan be simply and efficiently controlled, it will enable architects andspace planners to design more efficient HVAC systems, by reducing ormaximizing heat gain during those limited periods that require peak HVACsystem performance and consequently reducing air conditioning andheating capacity requirements. Instead of investing in expensiveover-capacity equipment to handle the limited excessive sunlight andcold days in any given year, the architects and space planners can relyon the glazed panel to reduce the peak demand times and therefore themaximum HVAC load capacity.

The known approaches to controlling the amount of light admitted throughglazing systems, however, are limited and are generally difficult orexpensive to construct and service. There is therefore a substantialneed for a flexible, inexpensive, reliable and readily serviceablesystem for achieving this purpose.

Prior approaches to controlling the level of light passing througharchitectural structures have been of only limited usefulness. Forexample, louver blind assemblies using pivoting flexible membersoperable inside a chamber formed by a double-glazed window unit havebeen suggested for this purpose. Such louver blinds require substantialsupport of the flexible members which, additionally, must be controlledfrom both their distal and their proximal ends. Furthermore, louverblinds are difficult and expensive to assemble, apply, operate, maintainand replace, and cannot be readily adapted for use in non-verticalapplications or in applications in which it is either desirable ornecessary to control the flexible members from only one end.

U.S. Pat. No. 6,499,255 provides another, more recent approach toaddressing this challenge. The '255 patent describes a unitarytransparent or translucent panel of controllable radiationtransmissivity comprising a plurality of rotatably-mountedradiation-blocking tubular members having at least one portion which issubstantially opaque and means for rotating the radiation-blockingmembers to block out varying amounts of the radiation striking the panelby varying the area of the opaque portions presented to the incominglight. It is key to this structure that the radiation-blocking membersbe mounted in a series of adjacent segregated tubular cells which makeup the unitary panel.

While the unitary panel described in the '255 patent represents animportant advance in the art, it has some shortcomings. For example,adjacent tubular members cannot abut each other due to the interveningclear or transparent walls of the tubular cells. Thus, when the tubularmembers are in the fully closed position, light still passes through theclear or translucent material of the unblocked cell walls between theadjacent radiation-blocking members. Also, if a tubular member fails,the entire panel must be removed and replaced. This may be prohibitivelycomplex and expensive in certain applications. Where the panels are partof a protected enclosure, removal of an entire panel will expose theinterior of the enclosure to the exterior environment which can beproblematic.

Additionally, in the design of the '255 patent the diameter of theradiation blocking members is constrained by the size of the cells—wherecircumstances make larger or smaller radiation-blocking membersdesirable or necessary due to economic or other reasons, the system ofthe '255 patent cannot accommodate them. For example, the maximum cellsize available following the teaching of the '255 patent is 30 mm×30 mmdue to manufacturing constraints in extruding the panels. Thus, a panelwidth of 1 meter by 30 mm in thickness or depth will require 33 tubularmembers as well as 33 related driven mechanisms which extend beyond theend of the panel. This is a very complex and expensive design whichcould be made substantially simpler and less expensive if the sameresult could be achieved with fewer larger diameter radiation-blockingmembers or with simpler drive mechanisms that preferably could besubstantially contained within the area defined by the panel.Furthermore, the unitary cellular panel structure of the '255 patentresists bending, making it difficult to use the system in architecturalapplications where tight radius bends are required. Additionally, thecellular-panel structure has insulation, soundproofing and structurallimitations arising from its maximum 30 mm thickness or depth that makeits use less than ideal in applications calling for high insulationvalues, substantial soundproofing and long span construction. Finally,the unitary cellular panel structure of the '255 patent does not permitthe use of different combinations of interior and exterior panel colorsand finishes as required or desirable in many architecturalapplications.

BRIEF SUMMARY OF THE INVENTION

It is one objective of this invention to provide atransparent/translucent panel unit in which the transmission of lightacross the system can be adjusted from almost full transparency ortranslucency to near total opacity. This is accomplished with twogenerally parallel spaced flat panels or sheets and a series ofelongated, transparent/translucent light-controlling members disposedbetween the panels and mounted for rotation about their longitudinalaxes. The spacing between the flat panels can be adjusted to accommodatedifferent sizes of light-controlling members, from as little as 1 inchto 6 inches or more. Also, panel units of a highly desirable thicknessor depth of about 2.75 to 4 inches or more can be produced to achieveoutstanding insulation, soundproofing and structural characteristics.This makes the panels ideal for use in applications calling for highinsulation values, substantial soundproofing and long span construction.

Once installed, the light-controlling members as well as othercomponents housed between the panels can be readily accessed by removingone of the two parallel panels, leaving the second panel in place toprotect areas enclosed by the panel system from exposure to the outsideenvironment. Additionally, in one preferred embodiment of the invention,the light-controlling members may be positioned in abutting relationshipto maximize the effectiveness of the system in blocking incoming lightwhen the panel system is in the fully closed position.

Rotation of the light-controlling members may be by the application ofrotary motion at one end (or less preferably at both ends) of eachlight-controlling member. The rotary motion may be applied to aplurality of the light-controlling members directly, as described, forexample, in the '255 patent, or it may be applied indirectly. Thus, inone particularly important aspect of the invention, circular engagementsurfaces are provided on adjacent light-controlling members. Thisenables the plurality of light-controlling members within a panel unitto be rotated by imparting rotary motion either manually or with amotorized drive to at least one of the light-controlling members whichtransmits the rotary motion indirectly across the contacting engagementsurfaces of adjacent light-controlling members to rotate thelight-blocking surfaces and vary the level of light passing through thepanel unit. Also, the use of two spaced-apart panels (rather than aunitary panel as in the '255 patent) makes it possible to house some orsubstantially all of the drive mechanism between the panels and thuswithin the panel unit, out of the way of other structural components.

This system can maintain a perfect balance between light transmissionand thermal performance, fostering a daylighted, comforting, livable andproductive environment all year long. It also conserves energy on peakdemand. The system may be fully automatic, with built-in intelligentlight controllers and an embedded program that senses the daylightoutside and manages the level of light and solar heat gain inside basedon the level of sunlight outside. This will enable users to controlnatural daylight and comfort levels in any space all day long, and allyear long, simply by setting desired light levels.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of this invention which are believed to be novel are setforth with particularity in the appended claims. The invention, togetherwith its objects and advantages, may be best understood by reference tothe following description, taken in conjunction with the followingdrawings, in which like reference numerals identify like elements in theseveral figures, and in which:

FIG. 1 is an elevational view of a portion of a prior art panel inaccordance with the teaching of U.S. Pat. No. 6,499,255;

FIG. 2 is a front elevation view of a panel unit in accordance with thepresent invention, attached to adjacent panel units which are shown inpart;

FIG. 2A is a partial enlarged view of the spacer rails of FIG. 2;

FIG. 2B is an elevational view of an alternate panel-joining arrangementin accordance with the invention;

FIG. 3 is an enlarged partial front elevation view of one panel joiningflange which may be used with the present invention;

FIG. 4 is a front elevation view of adjacent panel units angled withrespect to each other to form a roof ridge;

FIG. 5 is a partial enlarged view of a portion of the structureillustrated in FIG. 4;

FIG. 6 is a plan view, of a portion of the structure illustrated in FIG.4;

FIG. 7 is a perspective view of a honeycomb polycarbonate translucentpanel which may be used in constructing a panel unit in accordance withthe present invention;

FIG. 8 is a diagrammatic perspective view of a series of abuttinglight-controlling members;

FIG. 9 is a series of alternative designs of light-controlling memberswhich may be used in the present invention;

FIG. 9A is an enlarged partial view of a pair of particular lightcontrolling members in abutting position;

FIG. 9B is a partial view of a light-controlling member comprising aflat opaque member with a series of rings spaced along its length;

FIG. 9C is an alternate embodiment of a light-controlling memberstructure of FIG. 9 in which an opaque member is assembled into opposingslots of a hemispherical tube light-controlling member and then a secondhemispherical tube is assembled to the first tube to form a completetubular configuration;

FIGS. 10A-10C are diagrammatic representations of two light-controllingmembers in three difference relative positions, showing the passage ofvarying amounts of light;

FIG. 11A is a partial enlarged perspective view of a scalloped carriermember for supporting adjacent light-controlling members and FIG. 11B isa similar partial perspective view showing a pair of juxtaposedscalloped carrier members;

FIGS. 12A and 12B are front elevation views of, respectively, a seriesof adjacent light-controlling members of a single panel unit with topand bottom scalloped carrier members spaced therefrom and with the topand bottom scalloped members affixed together and holding thelight-controlling members in place;

FIG. 13 is an exaggerated diagrammatic representation taken in elevationview of a single light-controlling member resting in a scallop in acarrier member;

FIGS. 14A-14C are, respectively, a top plan view of a single panel unit,an end view thereof, and a cross-section thereof;

FIG. 15 is a representation of three alternative means for transmittingmotion across adjacent light-controlling members;

FIG. 16 is comprises end views of means for transmitting motion acrossadjacent light-controlling members; and

FIGS. 17A and 17B comprise alternative embodiments of the invention inwhich a metal screen and insulating materials are located within thepanel system.

DETAILED DESCRIPTION OF THE INVENTION

Turning first to FIG. 1, an elevational view of a transparent ortranslucent panel 10 in accordance with the teaching of prior U.S. Pat.No. 6,499,255 is shown. Panel 10 includes a series of half-cylinderlouvers 12 rotatably mounted in a series of adjacent, segregated cells16 separated by walls 17. Louvers 12 each have an opaque top surface 18.Thus, in the illustrated embodiment where the louvers are in the fullyclosed position, light rays 20 strike opaque surfaces 18, which blocklight transmission through the louvers. Unfortunately, the transparentor translucent material in the walls 17 between adjacent cells remainsunblocked, which means that light rays 22 will penetrate the panelthrough these walls. Thus, even with all of the louvers in the fullyclosed position, the panels of the '255 patent admit light: in onecommercial embodiment of this invention, the panels have been found toadmit a minimum of about 6% light transmission. Also, the panel of the'255 consists of one integral, hollow core, multi-cell panel withinserted radiation-blocking members in the cells, which means thatserviceability and maintenance options are limited.

The panel systems of the present invention are referred to as beingtransparent/translucent. It is intended to mean by this that the panelsystems range from transparent (transmitting light rays so that objectson one side may be distinctly seen from the other side) throughtranslucent (letting light pass but diffusing it so that objects on oneside cannot be clearly distinguished from the other side). Also, thepanel systems may be tinted. Typical tinting colors include white,bronze, green, blue, and gray, although other colors may be used.Further, the panels may have a matte finish. Finally, combinations ofdifferent top and bottom panels may be used, such as clear/clear,white/clear, clear/white, bronze/clear, green/clear, green/white,bronze/white, white/white, etc.

Also, when reference to “light” is made in the description of thepresent invention, it should be construed to include the spectral rangeof visible light as well as electromagnetic radiation below and/or abovethat spectral range.

Turning now to FIG. 2, a panel system unit 30 in accordance with theinvention is shown consisting of two generally flattransparent/translucent panels, including an interior panel 32 and anexterior panel 34. Panels 32 and 34 are generally parallel and areseparated a distance “x” by elongated spacer rails 36 with top andbottom ledges 37 which extend along the lateral edges 38, 40, 42 and 44of the interior and exterior panels. This spacing may be of any desiredsize, since the spacing of the panels can be adjusted to accommodatewhatever diameter is chosen. While panels 32 and 34 may be of anydesired width, currently preferred widths are 24, 48 and 60 inches.Also, while the panels may also be any desired length, it is currentlyintended that panels about 2 feet to 60 feet in length will be used.

The lateral edges of the panels may be provided with respective paneljoining flanges 46, 48, 50 and 52 for conveniently assembling the panelstogether. In one such panel-joining arrangement, the flanges each have asmooth outer face 54 and an inner face 56 with tooth-like detents 58a-58 c (FIG. 3), whose function will be explained below. A similarjoining flange structure is described, for example, in U.S. patent Re.36,976, the contents of which are incorporated herein by reference.Also, panels with different panel joining flange designs and otherpanel-joining arrangements may be used.

As seen best in FIG. 2A, spacer rails 36, in turn, each have an outerbracket 60 shaped as shown, to provide a middle attachment section 61and offset ends 62 and 64. The brackets are attached to the outersurface of each of the spacer rails by conventional means, withattachment section 61 centered along the rails, thereby defining top andbottom channels 66 and 68 between the outer surface of the spacer railsand the inner surface of the bracket. The channels are dimensioned toaccept flanges 48-52 in a tightly fitting manner to firmly and sealinglyjoin the panels under an elastic deformation of the detents. Thus, whenthe panels are pressed home to assemble the panel system unit with theinner surfaces of panels 32 and 34 abutting ledges 37, there isresistance to removal of either of the panels from these channels. Ifand when a repair is needed, it is necessary only to release one cornerof the panel flange with an appropriate tool, and then continue to zipit along the length of the panel to release the entire panel. The panelcan be reinstalled after the repair is completed by again pressing thepanels home to seat the panel flanges in the channels.

An alternate panel-joining arrangement is depicted in FIG. 2B. In thisembodiment, internal and external panels 32 a and 34 b may be anyappropriate sheet material. The sheets are held together in thisembodiment by retainers 36 a which extend along the opposite lateraledges of the sheets. Retainers 36 a include two channels 39 and 41 inwhich the lateral edges of the sheets snugly rest and a spacer 51carrying the flanges at the desired sheet spacing of the panel system.The retainers preferably are made of aluminum or of another metal whicheither inherently resists corrosion or is treated to resist corrosion.

Any number of fully assembled panel units 30 can be joined to adjacentpanel units to achieve the panel system width called for in a particularapplication. Adjoining panel units may be fixed to each other using aclamping system 70. This clamping system includes a bottom member 72with a base 74 and elongated bottom pedestals 76 and 77 along eachlateral edge of the base. An upstanding bracket 78 along the center ofthe base with a series of screw thread-receiving apertures 80 along itslength. Clamping system 70 also includes a top member 82 with anupstanding reinforcing strip 84 along its center and a series ofscrew-receiving apertures 86 running along the strip. Along each lateraledge of the top portion, a pair of elongated top pedestals 88 and 90 areprovided with apertures for receiving resilient sealing gaskets 92.

In order to join the adjacent lateral edges of the panel units, theclamping members are positioned as illustrated, with elongated bottompedestals 76 and 77 abutting the exposed surface of the interior panelsand sealing gaskets 92 of top pedestals 88 and 90 abutting the topsurface of the exterior panels. A series of screws 94 spaced, forexample, at intervals of about 8-16 inches, are passed through theapertures 86 and into the thread-receiving apertures 80, and screwedhome to lock the clamping member together and seal the connection fromoutside elements.

FIGS. 4 and 5 illustrate an alternate application of the invention whereadjacent panel units are angled with respect to each other to form aroof ridge. In this embodiment, a modified clamping system design 70′ isused. This modified clamping system generally corresponds to clampingsystem 70 except that base 74′ and top member 82′ are angled to producethe desired ridge slope.

A series of four panel units assembled to produce a panel system for usein a skylight is illustrated in FIG. 6. In this fully assembled system,the four panel units 30 a, 30 b, 30 c, and 30 d are each individuallyassembled and joined to adjacent panel units as illustrated in FIG. 2and described above.

The use of removably mounted interior and exterior panels facilitateseasy replacement of damaged panels without exposing the interior of theenclosed structure. Adding or replacing a double-layer on other glazingsystem, in contrast, would be significantly more difficult andexpensive, and could produce damage requiring repairs that interrupt thefunction of the architectural structure in which the panel system ismounted.

Thus, assuming for purposes of illustration that exterior panel of panelunit 30 b has to be removed to remedy a problem within the panel unit.This can be accomplished by inserting an appropriate tool at point A toremove the leading corner of the panel flange from its correspondingchannel and then continue to zip it along the length of the panel torelease the entire panel. This is repeated at point B whereupon theentire panel is removed, the problem is remedied and the exterior panelre-installed by positioning the flanges adjacent the channels andpressing the exterior panel home as describe earlier. It should be notedthat this entire repair operation can be accomplished without disturbingthe interior panel of the panel unit. Also, either of the sheets of thealternative panel-joining arrangement of FIG. 2B may be removed in asimilar fashion by slipping the appropriate channel from the edge of thesheet which is to be removed and reattaching the channel when the repairis completed.

A wide variety of different types of panels made of various transparentand translucent materials may be used, including, but not limited to,plastics (including, but not limited to, polycarbonates and acrylics),fiberglass, perforated metal fabric, or glass. It is preferred, however,that the panels have at least the appropriate light transmittingproperties and a minimum resistance to impact of about 10 ft/lb. Also, aUV-resistant architectural face can be co-extruded with the panel tominimize the need for periodic resurfacing.

In one preferred embodiment, a Pentaglas® honeycomb polycarbonatetranslucent panel available from CPI International Inc. (Lake Forest,Ill.) will be used. These polycarbonate panels are described in U.S.Pat. No. 5,895,701, which is incorporated herein by reference, have anintegral extruded honeycomb structural core consisting of smallhoneycomb cells approximately 0.16 inch by 0.16 inch which providesinternal flexibility to absorb expansion and minimize stress and resistsimpact buckling. The resulting design offers smaller spans between ribsupports, resulting in stronger durability, as well as superior lightquality, visual appeal, higher insulation and excellent UV resistance.The internal flexibility of the panels absorbs thermal expansion throughthe panel in all directions (on the x, y, and z axes). This minimizesstress in all directions and preserves dimensional stability. The panelsalso have a high impact absorbing and load bearing property, a goodratio of weight to strength, and UV protection on both sides of thepanel. The superior light diffusion capabilities ensure excellentquality of natural light. The panels are environmentally friendly,non-toxic, and made of 100% recyclable material.

A series of elongated rotatably mounted light-controlling members 100corresponding in length to the length of the panel units are disposedbetween panels 32 and 34, as represented in a diagrammatic perspectivefashion in FIG. 8. As described below, the light-controlling members maybe of a variety of different structures. In a preferred embodiment, thelight-controlling members will have a circular outer rotation surface(e.g., an elongated tube or a series of outer annular members disposedalong the light-controlling members generally perpendicularly to thelongitudinal axes of the light-controlling members) extending at leastabout 180° around their circumference. In the illustrated embodiment,the light-controlling members abut each other (tolerance about 1-3 mm)to maximize the light blocking capability of the system. This is apreferred embodiment of the invention. However, in alternativeembodiments, the light-controlling members may be spaced from each otherpermitting some light to pass between adjacent light-controllingmembers, so long as the circular engagement surfaces of adjacentlight-controlling members remain in contact.

A series of alternative designs of the light-controlling members 100 areillustrated in cross-section in FIG. 9. For example, a light-controllingmember 100 a may be used, comprising a generally elongated transparentor translucent tube 102 having a diameter “B”. A generally planarlight-blocking or opaque member 104 is positioned in the tube across itsdiameter by co-extruding the outside tubular wall and the light-blockingor opaque member or by inserting the light-blocking or opaque member ina preformed tube.

The light-blocking or opaque member need not be flat but may, forexample, be wider than the allowed space and inserted in a “bowed” orother configuration. In the illustrated embodiment, tube 102 may bereplaced by a series of annular members or rings 103 spaced along anopaque member 105 (FIG. 9B). In this embodiment, the opaque membershould be sufficiently rigid so that applying rotary movement to theopaque member at any point along its length will cause the entirelight-blocking or opaque member to rotate about its longitudinal axiswithout causing the opaque member to twist substantially out of itsinitial configuration.

The light-blocking members may be opaque or they may be translucent ortinted to a level which produces the desired degree of light-blocking.Also, the light-blocking members may be segmented into light-blocking oropaque portions and transparent/translucent portions. For example, in a40-foot panel unit with corresponding 40-foot light-controlling members,the first 10 feet of one or more of each of the light-blocking membersmay be opaque, the next 5 feet transparent/translucent, and the last 25feet opaque. Such a segmented arrangement might be used where it isdesired to maintain a lighted area at all times.

Light-controlling member 100 b is generally of the same design aslight-controlling member 100 a including a tube 106, except thatlongitudinal sills 108 project radially from the outer surface of thetube. When the tubes are positioned so that the sills abut at leastpartially as the tubes rotate (FIG. 9A), the range of motion of thetubes is limited by the abutting sills to 180°. Also, the sills may beeither opaque themselves (as shown) or coated with a light-blocking oropaque material. This provides enhanced light blocking when the sillsapproach and reach an abutting position since light between the tubes isblocked by the sills. Furthermore, the use of light-blocking or opaquesills in this fashion makes it possible to increase the spacing betweenthe adjacent tubes without sacrificing light blocking between the tubes,so long as the sills are also widened to insure that they extend intothe space between the adjacent tubes. Of course, tubes withlight-blocking or opaque sills as described above may also be arrangedso that the sills do not actually touch as the tubes rotate, which willpermit some light to pass between the sills when the light-controllingmembers are in the closed position. Lastly, the tubes may be providedwith only one light-blocking or opaque sill each or with more than twosills at varying locations about the circumference of the tubes.

Light-controlling member 100 c comprises a tube 110 with opaque-coatedouter sills 112 and a pair of opposing slots 114 and 116 formed at theinside diameter of the tube to receive an opaque member 118 which isassembled into the tube after it is formed. In all cases, the opaquemember is rendered opaque by known techniques, such as painting, bycoating with an opaque film, by applying an opaque plastic layer byco-extrusion, etc. Also, fire resistant materials such as metal slotsmay be used as the opaque member to improve the fire resistance of thepanel system. Additionally, different colors and designs may be appliedto the opaque members to increase the visual interest of the panelsystem as the opaque members move into the closed position. Indeed, theopposite sides of individual opaque members may be differently coloredor bear different designs to produce different visual effects byrotating the light-controlling members 180° from one fully closedposition to the other.

Another light-controlling member design is designated 100 d. This tubehas a generally hemispherical cross-section and preferably itscircumference extends to 180°. Although an opaque surface may becoextruded across the diameter of the tube (not shown), in theillustrated embodiment the tube 120 includes a pair of opposing slots122 and 124 at the inside diameter of the tube to receive an opaquemember 126 which is assembled into the tube after it is formed. Whenthis structure is used, a series of annular members or rings may bedisposed along the length of the light-controlling member to permitcomplete rotation of the light-controlling member. In anotheralternative embodiment, once the opaque member is assembled intoopposing slots 122 and 124, another tube 125 with a generallyhemispherical cross-section and lands 128 may be assembled to tube 120(e.g., by creating an adhesive bond or a clip-on type connection at thelands) to produce a complete 360° tubular configuration as seen in FIG.9C.

Light-controlling member 100 e comprises an opaque member 132 with asupporting wall 130, together forming an elongated light-controllingmember with a “T” shaped cross-section, as shown. The reinforcing rib 7adds rigidity to the opaque member and also helps position the opaquemember within a series of rings 128 which are spaced along thelight-controlling member. In a less preferred embodiment of theinvention, the reinforcing rib may be eliminated. Light-controllingmember 100 f, in turn, includes a series of annular members of rings 136and an opaque member 138 with generally perpendicular supporting walls140 and 142 which extend along the length of the tube and abut the ringsat their apex 143. Other tube configurations are illustrated in U.S.Pat. No. 6,499,255, and are incorporated herein by reference.

FIGS. 10A-10C are diagrammatic representations of two light-controllingmembers 100 d in three different positions. In FIG. 10A, the twolight-controlling members are in the “fully closed” position, with theopaque members 126 of the tubes 120 adjacent each other and fullyblocking incoming light 144. This figure should be contrasted with thedepiction of the prior art system of U.S. Pat. No. 6,499,255 in which inthe fully closed position depicted, light rays 22 penetrate the panelthrough the walls 17 between the cells 16. In FIG. 10B, tubes 120 havebeen rotated 90° so that the maximum amount of light 144 may pass by thetubes. Finally, in an intermediate position of the tubes as shown inFIG. 10C, only a portion of the light will pass.

In each of the embodiments of this invention, the opaque members may bereplaced with light-blocking members which are not opaque but rather aresemi-opaque so that a limited amount of light will pass in the fullyclosed position, as may be required or desired in certain applications.Also, the opaque or semi-opaque members may include photovoltaic solarcells to generate electricity, preferably in conjunction with means formaximizing the photovoltaic output by rotating the light-controllingmembers with movement of the sun across the sky to insure that thephotovoltaic solar cells continuously receive the maximum possiblesunlight exposure. Finally, where the sole objective is to generateelectricity, the opaque members may be replaced with transparent ortranslucent photovoltaic solar cells.

We turn now to FIGS. 11A, 11B, 12A and 12B. These figures illustratescalloped carriage members 150 each comprising a generally horizontalbase 152, and a series of hemispherical cut-outs or “scallops” 154 intheir top surface. Scallops 154 are intended to receive thelight-controlling members and are therefore slightly greater in diameterthan the light-controlling members. Thus, as illustrated in FIG. 13, thearea of contact between the outer surface C of the tube 102 and theinner surface of a scallop 154 is minimized, thereby minimizing thefriction between the two, as the light-controlling member is rotated.

In the fully assembled panel, support of the light-controlling membersmay be provided by a series of carriage members spaced along the panelfor supporting and horizontally positioning the light-controllingmembers adjacent each other. The scalloped carriage members may be usedsingly or in pairs, clamped together using a clamping spring 150, asdepicted in FIG. 12B. When the carriage members are used with lightcontrolling members with sills, as in 100 c of FIG. 9, the sills shouldbe cut away to provide clearance for the carriage members. Furthermore,since the use of sills permits increased spacing between adjacentlight-controlling members, the spacing between the scallops can beincreased, permitting a concomitant increase in the surface area of theabutting surfaces 151 and 153 (FIG. 12A) of the carriage members and theoption of placing connecting members (e.g., hook and loop (Velcro®)connectors, self-tapping screws, snap fasteners, etc.) at those abuttingsurfaces to help lock the carriage members together.

The carriage members preferably will be made of a low friction materialsuch as a low friction engineered plastic like polycarbonate or a lowfriction metal like aluminum, and the scallops and/or the portions ofthe light-controlling members riding in the scallops may be coated witha slippery coating such as teflon. Also, when a hemisphericallight-controlling member is used (e.g., 100 d), rings may be disposed onthe light-controlling member at the point of contact with the scallopsto extend the range of rotation. When hemispherical light-controllingmembers with sills are used, the sills may be cut away to permit annularmembers to be disposed on the light-controlling member at the point ofcontact with the scallops.

A fully assembled panel system 160 is shown in FIGS. 14A, 14B, and 14C(respectively, top plan, side elevation and cross-sectional views), witha series of scalloped carrier members 150A, 150B and 150C spaced withina panel unit comprising interior panel 162, exterior panel 164, and aseries of light-controlling members 166 within the panel system restingon the scalloped carrier members which support the light-controllingmembers.

Turning now to FIG. 15, three alternative means for transmitting motionacross adjacent light-controlling members are illustrated. In the firstmotion-transmitting arrangement, an annular endcap 170 is attached toone end of a light-controlling member 172 and the endcap is providedwith a band 174 of a high coefficient of friction material, such asrubber or polyurethane, so that circular motion imparted to onelight-controlling member in the series of adjacent members will impartmotion to the remaining members due to the frictional linkage achievedby the high coefficient of friction material positioned in alignment onadjacent members. One or more bands 174 may also be applied along thelight-controlling members when they are tubular, either in lieu of theband on endcap 170 or in addition to it. Also, it is preferred that thebands be clear or translucent, particularly when they are disposed alongthe light-controlling members. Additionally, where the light-controllingmembers have sills, as discussed above, the sills will be cut away toprovide clearance for the rings.

In the second motion-transmitting arrangement, one or more notched bands176 are positioned along a light-controlling member 178 and aligned sothat the intermeshed bands of adjacent light-controlling memberstransmit motion imparted to one member across the series of intermeshedmembers. Such intermeshing bands may also be used on an endcap asdescribed above and further use of clear or translucent intermeshingbands is preferred. Also, as in the prior embodiment, where thelight-controlling members have sills as discussed above, the sills willbe cut away to provide clearance for the rings.

In the third motion-transmitting arrangement, the outer surface 182 ofeach of light-transmitting members 180 is provided (as by extruding)with a cogwheel cross-section, as shown, including a series of teeth 184extending along their length so that the adjacent light-transmittingmembers intermesh to transmit motion imparted to one member (as by adrive motor (not shown)) across the series of intermeshed members. Anopaque member 188 is preferably positioned within the cogwheelcross-section between a diametrically opposing pair of teeth 184 a and184 b so that the opaque member extends into the teeth and is supportedalong its lateral edges within the opposing teeth. This embodiment hassome significant advantages. First, the intermeshing teeth provide awide tolerance as to fit between adjacent light-controlling members andtolerance to dirt or other extraneous matter which may find its way intothe area. Second, since the opaque member extends into the teeth and issupported along its lateral edges within the opposing teeth in theclosed position, the opaque members of adjacent light-controllingmembers will overlap, blocking the passage of light between adjacentlight-controlling members.

End views of the light-transmitting members resting within a series ofthree panel systems, 186, 188 and 190 as described above are illustratedin FIG. 16. In panel system 188, however, a small gear 192 is locatedbetween the adjacent spaced light-controlling members to enable thelight-controlling members to rotate in the same direction as theadjacent notched bands intermesh with the wheels.

The above and other methods may be used for rotating adjacentlight-controlling members where rotary motion is imparted to one or more(but not all) of the adjacent light-controlling members either manuallyor by motorized means, as represented diagrammatically by feature M inFIG. 12A. Any of the mechanisms described in U.S. Pat. No. 6,499,255,for example, may be used for imparting such rotary motion.

Turning now to FIGS. 17A and 17B, a further embodiment of the presentinvention is disclosed in which space 200 is provided above the plane ofthe adjacent light-controlling members in the panel unit. Thus, forexample, in FIG. 17A, a panel-joining system 202 much like that ofpanel-joining system 36 in FIG. 2 is shown, except that thispanel-joining system 202 has an elongated upstanding bracket 204 and isused in conjunction with elongated spacer rails 208, shown in side viewat the right of the figure. A different enlarged panel-joining system210 is used in the embodiment of FIG. 17B with different panels, and thepanels are held together by a different attachment mechanism. In bothcases, enlarged clamps 209 are used to joint adjacent panel units.

In both the embodiments of FIGS. 17A and 17B, a series of “I” beams 208are positioned at intervals between the lateral edges of the interiorand exterior panels to create an air space 210 between the panels. InFIG. 17A, a panel of a non-combustible generally light-transmittingmaterial, such as a metal screen 212, is positioned above thelight-controlling members and held tautly in position. In FIG. 17B, aseries of “I” beams 208 are positioned at intervals between the lateraledges of the interior and exterior panels to create an air space 210between the panels. In FIG. 17A, a layer of light transmittingfire-resistant insulating material, such as loose glass fibers 214, isdisposed immediately above the screen in air space 210 to add thermalinsulation and to enhance the fire resistance of the panel system. Thescreen and insulating material prevent or delay the passage of burningparticles through the panel system, in accordance with the requirementsof ASTM E-108 Class A Fire Rating Requirements. The resulting panelsystem thus provides the light transmission and control characteristicsof the other embodiments of the invention as well as improved fireresistance.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

1. A transparent/translucent panel unit for varying the level of lightpassing therethrough comprising: a pair of spaced-aparttransparent/translucent panels; and a plurality of light-controllingmembers positioned between the panels and mounted for rotation abouttheir longitudinal axes, the light-controlling members having at leastone substantially light-blocking surface; and the light-controllingmembers each having at least one engagement surface in contact with anengagement surface of each of its adjacent light-controlling members fortransmitting rotary motion across contacting engagement surfaces ofadjacent light-controlling members to thereby rotate the light-blockingsurfaces and vary the level of light passing through the panel unit,whereby the plurality of light-controlling members may be rotated byimparting rotary motion to at least one of the light-controllingmembers.
 2. The transparent/translucent panel unit of claim 1 in whichthe panels are made from a material chosen from the group consisting ofplastics, fiberglass, perforated metal fabric, and glass are generallyparallel to each other.
 3. The transparent/translucent panel unit ofclaim 1 in which the panels are chosen from the group consisting ofhoneycomb cross-section polycarbonate translucent panels and rectangularcross-section polycarbonate translucent panels.
 4. Thetransparent/translucent panel unit of claim 1 in which a plurality ofrings are spaced along the outer circular surface of the tubes generallyperpendicularly to the longitudinal axes of the tubes to achieverotation of the light-controlling member through 360° and the engagementsurfaces of the light-controlling members are circular.
 5. Thetransparent/translucent panel unit of claim 4 in which the circularengagement surfaces extend at least about 180° about the circumferenceof the light-controlling members.
 6. The transparent/translucent panelunit of claim 4 in which the circular engagement surfaces extend 360°about the circumference of the light-controlling members.
 7. Thetransparent/translucent panel unit of claim 1 in which thelight-controlling members are elongated tubes having an outer circularsurface extending at least about 180°.
 8. The transparent/translucentpanel unit of claim 7 in which the light-controlling members areelongated tubes having an outer circular rotational surface extending atleast about 360°.
 9. The transparent/translucent panel unit of claim 7in which the light-blocking surfaces are generally planar and positionedacross the diameter of the tube.
 10. The transparent/translucent panelunit of claim 9 in which the tube and light-blocking member areco-extruded.
 11. The transparent/translucent panel unit of claim 1 inwhich the light-controlling members comprise a generally planarlight-blocking surface supported within a plurality of rings spacedlongitudinally along the light controlling member to achieve rotation ofthe light-controlling member through 360°.
 12. Thetransparent/translucent panel unit of claim 1 in which thelight-controlling members are tubular and include longitudinal sillsprojecting radially from the outer surface of the tubes.
 13. Thetransparent/translucent panel unit of claim 12 in which the sills arelight-blocking.
 14. The transparent/translucent panel unit of claim 13in which adjacent light-controlling members are positioned so that thesills at least partially abut as the light-controlling members rotate.15. The transparent/translucent panel unit of claim 1 in which thelight-controlling members include a first tube with a hemisphericalcross-section and an opaque surface across the diameter of the tube anda second tube with a hemispherical cross-section attached across thediameter of the first tube to provide a 360° tubular outer circularrotation surface.
 16. The transparent/translucent panel unit of claim 1in which the light-blocking surfaces include photovoltaic solar cells.17. The transparent/translucent panel unit of claim 1 in which thelight-blocking surfaces are substantially opaque or substantiallysemi-opaque.
 18. The transparent/translucent panel unit of claim 1 inwhich the engagement surfaces comprise bands of a high coefficient offriction material positioned in alignment on adjacent light-controllingmembers.
 19. The transparent/translucent panel unit of claim 1 in whichthe engagement surfaces comprise one or more notched bands positioned inalignment on adjacent light-controlling members.
 20. Thetransparent/translucent panel unit of claim 1 in which thelight-controlling members comprise elongated tubes having a cogwheelcross-section including a series of teeth extending along their lengthso that light-transmitting members intermesh to transmit motion impartedto one member across a plurality of intermeshed light-controllingmembers.
 21. The transparent/translucent panel unit of claim 20 in whichthe light-blocking member is positioned within the cogwheelcross-section between a diametrically opposed pair of teeth.
 22. Thetransparent/translucent panel unit of claim 1 including a panel of anon-combustible generally light-transmitting material positioned withinthe panel unit above the light-controlling members.
 23. Thetransparent/translucent panel unit of claim 1 including an air spacebetween the panels and a light-transmitting fire resistant insulatingmaterial disposed within the air space.
 24. A transparent/translucentpanel system for varying the level of light passing therethroughcomprising: a plurality of individually assembled panel units joined toadjacent panel units, the panel units including; a pair of spaced-aparttransparent/translucent panels; and a plurality of light-controllingmembers positioned in the space between the panels and mounted forrotation about their longitudinal axes, the light-controlling membershaving at least one substantially light-blocking surface; and thelight-controlling members each having at least one engagement surface incontact with an engagement surface of each of its adjacentlight-controlling members for transmitting rotary motion acrosscontacting engagement surfaces of adjacent light-controlling members tothereby rotate the light-blocking surfaces and vary the level of lightpassing through the panel unit, whereby the plurality oflight-controlling members within the units may be rotated by impartingrotary motion to at least one of the light-controlling members.
 25. Atransparent/translucent panel unit for varying the level of lightpassing therethrough comprising: a pair of spaced-aparttransparent/translucent panels; and a plurality of elongated tubularlight-controlling members positioned between the panels and mounted forrotation about their longitudinal axes, the light-controlling membershaving at least one substantially light-blocking surface andlongitudinal, light-blocking sills projecting radially from the outersurface of the tube; and at least one circular engagement surface incontact with an engagement surface of its adjacent light-controllingmembers for transmitting rotary motion across contacting engagementsurfaces of adjacent light-controlling members, whereby the plurality oflight-controlling members may be rotated by imparting rotary motion toat least one of the light-controlling members to thereby rotate thelight-blocking surfaces and vary the level of light passing through thepanel unit.